This article has multiple issues. Please help improve it or discuss these issues on the talk page. (Learn how and when to remove these messages) This biography of a living person relies too much on references to primary sources. Please help by adding secondary or tertiary sources. Contentious material about living persons that is unsourced or poorly sourced must be removed immediately, especially if potentially libelous or harmful. Find sources: "Masanori Ohya" – news · newspapers · books · scholar · JSTOR (September 2010) (Learn how and when to remove this message) This biography of a living person needs additional citations for verification. Please help by adding reliable sources. Contentious material about living persons that is unsourced or poorly sourced must be removed immediately from the article and its talk page, especially if potentially libelous. Find sources: "Masanori Ohya" – news · newspapers · books · scholar · JSTOR (September 2010) (Learn how and when to remove this message) (Learn how and when to remove this message)

Masanori Ohya (大矢 雅則, Ōya Masanori, born 1947) is a Japanese mathematician.

After he received a Ph.D. in Mathematical Physics and Information Science and Dr.Sc., he continuously worked on operator algebra, quantum entropy, quantum information theory and bio-information. He achieved results in the fields of quantum information and mathematical physics. In particular, he proposed his version of quantum mutual entropy.^[1] Note this quantity is not the same as Holevo's chi quantity or coherent information, though each of them plays important role in quantum information theory. The information theoretic meaning of Ohya's quantum mutual information is still obscure.

He also proposed 'Information Dynamics' and 'Adaptive Dynamics', which he applied to the study of chaos theory, quantum information and biosciences as related fields.^{[clarification needed]}

Ohya studied multiple topics for more than thirty years, relating to quantum entropy, quantum information, chaos dynamics and life science. His main accomplishments are as follows:

1. Elucidation of Mathematical Bases of Quantum Channels,
2. Formulation of Quantum Mutual Information (Entropy),
3. Information Dynamics,
4. Analysis of Quantum Teleportation,
5. Quantum Algorithm,
6. Proposal of Adaptive Dynamics,
7. Applications to the life sciences.

They are explained in this book Watanabe 2007.

Academic Appointments:

• 1987–present: Professor, Department of Information Sciences, Tokyo University of Science
• 2004–2006 Dean, Graduate School of Science and Technology, Tokyo University of Science
• 2002–2006 Committee, International Institute of Advanced Study in Kyoto
• 2006–present: Dean, Science and Technology, Tokyo University of Science

Università di Roma II, Copernicus University, Jena University and many others.^{[clarification needed]}

Member of the Editorial Board of International Journals:

1. Infinite Dimensional Analysis, Quantum Probability and Related Topics;
2. Reports on Mathematical Physics;
3. Editor-in-chief of the Editorial Board of the journal Open Systems & Information Dynamics
4. Amino Acid

• M.Ohya and D. Petz (1993) Quantum Entropy and its Use, Springer-Verlag, TMP Series.
• R.S.Ingarden, A.Kossakowski and M.Ohya (1997), Information Dynamics and Open Systems, Kluwer Academic Publishers.
• M.Ohya (1999), Mathematical foundation of quantum computer, Maruzen Publishing Company.

• Watanabe, Noboru (2007), Selected papers of M. Ohya, World Scientific Publishing Co. Pte. Ltd., ISBN 978-981-279-419-2

• Web page at Tokyo University of Science